Graphs: 30 Years 1969 – 1999

Graphs for 30 years of the lake’s 45 year history showing the lowest level each year.

Table: 48 Years 1968 – 2015

Table of monthly lake levels for the last 45 years In response to a number of questions, here is the information that Toledo-Bend.Com has come up with on the historic levels of the lake from the period of 1969 through 2012. Some of this information seems to be available only in graph form; from 1986 it is available as hard data, though – which we have painstakingly parsed out for you. You didn’t really want to read over 9,000 daily lake level readings, did you? So, here are about 300 monthly levels. JANUARY, 2012: We got the daily lake levels from 1968 – 1986 and now have a complete history of the monthly average (1968-1999) or mean (1999-2011) levels. A BIG THANK YOU To Mr. David Barnhill of Many, LA! He found records of the lake level, day-by-day from its inception in 1968 – 1986 and has furnished those to Toledo-Bend.Com – which filled in the big blank spot in lake leves from 1968 – October 1986 and now gives a complete history of the levels of Toledo Bend throughout its existance! -1/14/2012

Toledo Bend Reservoir at HISTORIC Level!

Thursday 3/10/2016 Toledo Bend Lake hit a historic high level at the dam of 174.36 MSL at about 6:00 AM. The following pictures were taken at 1:00 PM March 10, 2016 when the SRA Louisiana had brought the lake rise under control and it had actually gone down about an inch to 174.25 MSL. There were 9 gates open 22 feet (the other 2 gates are undergoing maintenance) and Generator was running. Total release was 207,644 cubic feet per second (CFS) of water – that’s just over 1.5 million gallons per second! It is enough to fill 7 Olympic swimming pools every 3 seconds. The water flowing through the gates was sill a few inches below the gate openings, though, because the water is constricted as to comes into the passage ways for the gates – actually flowing downhill to the gates! The most the gates had ever been opened before was 11′ with a flow of 99,000 CFS.

Graphs of lowest lake levels for the years 1969 – 1999

Toledo Bend Reservoir – Lake Level MSL 1968 – 2015

Monthly average/mean level in feet above MSLAverage for 1968 – Oct, 1999 – Mean for Oct, 1999 – Mar, 2011 – mostly – for some months data was missing and had to be gathered and it was averaged. In spot checking – Average from Mar, 2011 – present, we found the differences between average and mean to be less than 0.02 ft. For 2012 the levels are mean for each given month.

NOTE: Lake is low in 1968 because that is when it is filling up! Notice how quickly it rose 24 feet from January through May! 1968 is not included in overall average figures at bottom for this reason

Jan

Feb

Mar

Apr

May

Jun

Jul

Aug

Sep

Oct

Nov

Dec

1968

147.86

152.40

155.96

165.54

171.21

172.37

172.42

172.20

172.25

172.06

171.99

172.78

1969

171.13

172.00

172.76

171.98

172.20

171.49

170.56

169.53

168.21

167.35

167.25

167.85

1970

169.15

169.74

171.22

170.99

171.35

171.31

171.04

170.05

169.45

169.01

170.02

170.17

1971

169.58

169.54

169.69

169.67

169.92

169.56

168.96

169.15

168.89

168.68

169.02

169.94

1972

170.64

170.04

170.60

171.38

171.38

170.30

170.20

169.24

167.36

166.49

167.95

169.95

1973

171.20

171.49

172.25

172.40

172.51

172.28

171.91

171.02

170.06

169.89

171.62

172.40

1974

172.65

172.14

171.50

171.91

171.80

171.48

170.88

168.99

168.06

168.61

171.19

172.42

1975

171.98

172.23

171.39

170.24

172.19

172.24

171.89

170.60

168.66

167.78

168.27

168.45

1976

169.22

169.76

170.29

170.34

171.75

172.05

172.11

170.05

168.10

167.09

167.08

167.84

1977

168.54

169.55

170.88

171.58

171.85

170.89

169.84

168.55

167.36

166.33

166.19

166.62

1978

167.59

169.48

169.80

170.45

170.85

170.56

169.32

168.35

168.67

168.71

168.53

169.22

1979

171.35

172.00

171.68

172.16

172.09

172.12

171.05

170.47

169.35

168.88

169.25

169.15

1980

169.16

171.01

170.23

171.95

172.16

171.63

170.54

169.22

168.22

167.21

167.13

167.02

Jan

Feb

Mar

Apr

May

Jun

Jul

Aug

Sep

Oct

Nov

Dec

1981

166.90

167.06

167.52

167.57

168.07

170.66

171.72

169.63

168.92

168.76

169.18

169.43

1982

169.45

169.88

169.80

171.00

171.34

170.92

170.93

169.64

168.59

168.30

168.27

170.70

1983

170.78

171.46

171.21

170.33

171.46

171.79

170.50

169.37

168.81

168.41

168.16

169.79

1984

169.26

170.11

171.08

170.61

171.21

171.03

169.53

168.45

167.92

168.17

169.11

169.12

1985

168.97

169.75

170.73

170.54

171.90

171.51

170.18

168.75

167.81

167.52

169.41

171.45

1986

170.51

169.25

169.24

169.76

171.16

172.50

171.85

170.13

169.10

168.498

167.866

170.195

1987

169.525

169.524

171.868

170.037

169.307

168.989

168.403

166.545

165.788

165.193

165.761

167.911

1988

170.047

169.107

169.829

170.373

169.89

168.875

168.103

167.685

167.044

166.442

166.183

167.076

1989

168.999

169.523

169.726

171.546

171.873

172.56

172.292

171.148

169.481

168.101

167.798

167.358

1990

169.109

172.25

170.572

170.973

172.271

172.259

170.682

168.759

167.482

166.935

167.292

168.439

1991

171.581

171.836

171.504

171.505

172.491

171.506

171.174

170.474

169.103

166.292

165.287

166.304

1992

169.193

171.876

172.593

171.274

170.981

171.517

171.384

169.926

168.574

167.645

167.664

168.308

1993

170.766

170.137

171.214

172.159

170.79

170.678

171.076

168.874

166.164

165.008

165.377

165.499

1994

165.86

168.635

170.827

170.299

171.662

171.629

170.848

170.928

169.128

169.4

169.098

168.831

1995

171.562

171.926

172

171.56

172.042

171.571

170.577

168.808

166.858

165.783

165.478

165.528

Jan

Feb

Mar

Apr

May

Jun

Jul

Aug

Sep

Oct

Nov

Dec

1996

166.044

165.872

165.626

165.663

165.817

165.609

165.281

165.105

165.227

165.639

165.803

167.178

1997

169.031

170.966

172.831

172.593

172.308

172.061

171.654

170.893

169.7

169.125

168.41

169.045

1998

171.876

172.535

172.163

170.737

170.24

169.191

167.41

165.274

164.864

165.85

167.958

169.746

1999

171.849

171.738

170.197

170.557

170.271

170.793

171.006

169.16

167.425

166.776

166.365

166.246

2000

166.111

165.902

166.309

169.120

170.894

171.389

171.654

169.826

167.960

166.945

167.621

168.779

2001

170.543

171.951

172.861

171.861

170.920

171.317

170.812

168.964

166.697

163.544

163.707

167.937

2002

170.499

170.173

170.012

171.967

171.836

171.787

170.775

168.836

166.840

166.338

168.246

168.859

2003

169.934

169.972

172.085

171.039

170.827

170.669

170.335

168.771

167.264

166.325

166.477

167.294

2004

167.941

171.605

171.619

170.288

172.144

172.097

171.957

170.278

168.596

168.467

169.172

170.029

2005

169.051

169.972

169.908

170.670

170.088

168.954

167.476

165.512

163.611

163.572

163.097

162.905

2006

162.974

164.776

166.639

168.159

168.420

167.210

165.626

163.635

162.088

162.923

165.144

165.444

2007

170.294

170.360

169.964

170.845

171.107

170.933

172.019

171.481

169.603

167.914

167.673

167.946

2008

168.425

169.496

170.695

172.320

171.886

171.476

170.350

168.533

168.118

167.745

167.863

168.298

2009

168.477

168.751

169.936

171.473

171.936

171.286

169.822

168.985

168.318

169.805

172.357

170.718

2010

169.868

170.180

171.857

170.537

170.218

169.177

168.274

167.701

166.148

164.414

164.062

163.818

Jan

Feb

Mar

Apr

May

Jun

Jul

Aug

Sep

Oct

Nov

Dec

2011

163.877

164.602

164.574

164.371

163.853

163.318

162.642

161.793

160.954

160.188

159.781

160.324

2012

162.28

164.92

168.86

170.50

170.29

169.35

169.32

168.97

168.52

168.42

167.77

167.55

2013

169.04

169.03

169.17

170.06

170.37

170.35

169.26

168.07

167.44

167.57

168.25

168.36

2014

168.77

169.17

169.73

170.54

171.04

171.14

171.29

171.22

170.37

169.04

168.15

168.31

2015

169.54

169.18

171.78

172.33

172.33

172.53

171.84

170.36

168.65

167.77

169.83

172.04

Average Level for 48 years 1969 – 2015

AVG

169.176

169.843

170.401

170.642

170.920

170.734

170.134

168.885

167.690

167.122

167.512

168.249

Jan

Feb

Mar

Apr

May

Jun

Jul

Aug

Sep

Oct

Nov

Dec

2016

SOURCE: USGS (primarily) – As these figures were obtained from different databases, there is some difference; the figures for 1986 – September, 1999 are monthly AVERAGES calculated by the webmaster from daily figures (yes, about 5,000 days worth!!!); the figures subsequent to September, 1999 are the mean levels as obtained from USGS (well, most are; a few we had to research and calculate since they weren’t provided). In spot checking, we found the differences between average and mean to be less than 0.02 ft.